AES Semigas


13 October 2021

Transphorm wins $1.4m DARPA contract to build on work with ONR

Transphorm Inc of Goleta, near Santa Barbara, CA, USA — which designs and manufactures JEDEC- and AEC-Q101-qualified gallium nitride (GaN) field-effect transistors (FETs) for high-voltage power conversion applications — has been awarded a $0.9m contract (with a $0.5m option) by the US Defense Advanced Research Projects Agency (DARPA).

Contract W31P4Q-21-C-0009 commissions Transphorm to explore performance and cost boundaries for manufacturing an alternative nitrogen-polar (N-polar) GaN solution for DoD and commercial radio frequency (RF)/millimeter-wave (mm-wave) applications. Transphorm will be responsible for delivering the epiwafer technology, whereas sub-contractor University of California, Santa Barbara (UCSB) will fabricate the RF/mm-wave transistors.

The new project builds on Transphorm’s history as well as ongoing work with the US Office of Naval Research (ONR) to establish a domestic resource and supply for RF GaN epiwafers, with emphasis on N-polar GaN, a technology that is proven to deliver greater benefits than today’s more commonly used gallium-polar (Ga-polar) GaN for RF and mm-wave applications. Transphorm will explore the use of sapphire substrates to achieve greater cost efficiency for N-polar GaN solutions compared with conventional Ga-polar on silicon carbide (SiC) solutions. The work output is expected to yield a stable, high-quality thin-epi structure, with its capability established by the high-performance transistors.

Transphorm’s team is targeted at meeting the following program objectives regarding N-polar GaN-on-sapphire:

  • establish the overall value proposition;
  • define the high-performance parameter space;
  • define the viability of building the epiwafers.

“This project, coupled with our ongoing work to scale manufacturing with ONR support, is an incredible opportunity for Transphorm to grow its position as a premium RF epiwafer supplier, our second business vertical,” says Dr Umesh Mishra, chief technology officer & co-founder of Transphorm. “The goal now is to take that foundation and enable our RF epi customers to achieve more efficient RF power for the dollar,” he adds. “Sapphire is an attractive material choice for this purpose but has historically been dismissed as it has low heat conductance. We believe that, with innovative engineering, the program team can overcome that limitation.”

The potential value of N-polar GaN in RF/mm-wave applications, as well as possibly for future power electronics, is appealing given its extraordinary efficiencies at frequencies as high as 94GHz, comments Transphorm. It is primed to directly benefit DoD systems along with applications for 5G, 6G and beyond, the firm adds.

See related items:

Transphorm selects Veeco MOCVD platform for GaN-based power & 5G RF devices

Transphorm awarded $15.9m extension to $2.6m base ONR contract to establish US source of GaN epi

Tags: Transphorm GaN-on-Si GaN HEMT